沁水盆地南部樊庄区块地面集输工艺优化与思考

Optimization of ground surface gathering and transportation process in the Fanzhuang Block,southern Qinshui Basin

中国石油天然气股份有限公司"十一五"期间在没有任何经验可借鉴的情况下在山西沁水盆地南部建成了我国第一个规模化、商业化、数字化的煤层气田,该气田边试验、边开发、边建设的发展模式给地面集输系统的合理布局带来了新的难题。为此,根据煤层气田的地质、气藏特征及气质组分特点,通过理论研究及现场试验,提出了地面建设新模式和地面集输工艺的优化措施:①简化低压集气工艺;②成功应用非金属管材;③采用井间枝上枝串接工艺;④采用越站集输工艺;⑤实现自动化控制及数字化管理;⑥应用三甘醇脱水技术;⑦采用集成过滤分离器;⑧煤层气集中处理、规模化外输;⑨实行低成本开发。同时,还对在实际生产中暴露出来的采气管线积水问题、气质净化问题、压缩机的适应性问题、湿气计量问题、山区电力线路与采气管线的敷设问题、地理信息系统建设问题、采气半径与集气站数量的关系问题、煤层气田标准化设计及模块化建设问题、压缩机的备用问题和煤层气销售市场定位问题进行了探讨,并给出了相应的建议。

Although without any available reference,the first large-scale,commercial,and digitalized CBM gas field in the Qinshui Basin,Shanxi Province,was successfully built by the PetroChina during the period of the Eleventh Five-Year Plan.However,the production of this field together with pilot tests or being under construction surely brings about problems for the reasonable layout of its ground surface gas gathering and transmission lines.In view of this,according to the characteristics of reservoirs,geological structures,and gas quality and components of this field,theoretical studies and field practices are performed.On this basis,the following optimization measures are presented for the ground construction and surface gas gathering process:(1)to simplify the low-pressure gas gathering process;(2)to smoothly use nonmetallic pipe materials;(3)to adopt the branch-by-branch cascade connection between wells;(4)to directly transport the low-pressure gases to the destination by stepping across some gathering stations;(5)to realize automatic control and digitalized management;(6)to apply the TEG dehydration system;(7)to use integrated filter separators;(8)to perform the centralized CBM treatment and commercial transportation services;(9)to practice low-cost development.Besides,a deep investigation was made into the following problems and the corresponding solutions in the actual production:water accumulation along gas gathering lines,coal ash mixed in the CBM gas,the adaptability of the existing compressors,the mete ring of wet gas,the laying mode of electric power lines and gas gathering lines in mountainous areas,the construction and use of Geographic Information System(GIS),the relationship between the radius(the distance from the well to the station)and the number of gas gathering stations,the standardized design and modularization of the field,the preparation of spare compressors,and shale gas sale market positioning,etc.This study provides reference for the rapid development of CBM fields in the next Twelfth Five-Year Plan in China.